23 lines
1.1 KiB
TypeScript
23 lines
1.1 KiB
TypeScript
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// Compile-time guard for the branded money types. Not imported anywhere (so it
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// never ships in a bundle); `npm run typecheck` type-checks it via the tsconfig
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// include, and each `@ts-expect-error` asserts the following line IS a genuine
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// type error. If the cents/dollars branding ever regresses, one of these lines
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// stops erroring and typecheck fails loudly ("unused @ts-expect-error").
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import { formatUSD, formatCentsUSD, asCents, asDollars, centsToDollars } from './money';
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const cents = asCents(1234); // $12.34 as integer cents
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const dollars = asDollars(12.34); // $12.34 as dollars
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// ✅ Correct unit → compiles fine.
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formatUSD(dollars);
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formatCentsUSD(cents);
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formatUSD(centsToDollars(cents)); // cross the boundary explicitly
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// ❌ Unit mixups → compile errors (the class of bug we keep fixing).
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// @ts-expect-error cents can't be formatted as dollars (would render 100× too big)
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formatUSD(cents);
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// @ts-expect-error dollars can't be formatted as cents
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formatCentsUSD(dollars);
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// @ts-expect-error a raw number must be branded (asDollars/asCents) first
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formatUSD(1234);
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